Preparation of Arabidopsis nuclei and nucleoli

We describe a method for isolating nuclei from cultured Arabidopsis cells. The same method can be used to further isolate nucleoli. Cell walls are first digested to yield protoplasts, which are purified by flotation on a Percoll gradient. Mechanical homogenisation is used to release nuclei, or with more homogenisation, nucleoli. These fractions are most easily purified by gentle centrifugation. The method has been used for proteomic analysis of nucleoli, as well as for biochemical studies. We also describe a method for immunological labelling of isolated nuclei.